The Immunohematological Reference Center is available to meet increasing needs for serological reagents that identify dog red cell antigens (DEA) and the dog histocompatibility antigens (DLA). The center maintains supplies of reagents and provides typing services to qualified investigators of multiple disciplines that require more completely characterized canine models for studies in transplantation immunology, coagulation deficiency states, tumor immunology, immunohematological problems, and immunopathological conditions. The center is a focus for collaborative efforts at local, national and international levels with invesitgators interested in the major histocompatibility complex of the canine. The center is committed to a program of standardization of serological tests and notation systems that characterize these immunogenetic markers of the dog. The specific aims of the center are compatible with the program statement of the Laboratory Animal Science program of the Animal Resources Branch and supportive of the program guidelines of the National Advisory, Heart and Lung Council, Special Animal Model Resources for Thrombotic and Hemorrhagic Disorders.